useKonamiCode.js

const getKeyName = keyCode => {
  switch (keyCode) {
    case 37:
      return "left";
    case 38:
      return "up";
    case 39:
      return "right";
    case 40:
      return "down";
    case 65:
      return "A";
    case 66:
      return "B";
  }
};

const isKonamiCode = codes => {
  return codes.join(" ") === "up up down down left right left right B A";
};

const useKonamiCode = () => {
  const [keys, setKeys] = useState([]);
  let timeout;
  document.onkeydown = e => {
    clearTimeout(timeout);
    setKeys(currentKeys => [...currentKeys, getKeyName(e.keyCode)]);
    timeout = setTimeout(() => {
      setKeys([]);
    }, 3000);
  };

  return {
    isKonamiCode: isKonamiCode(keys),
    keys
  };
};